Genetic diversity of Brazilian strains of porcine circovirus type 2 (PCV-2) revealed by analysis of the cap gene (ORF-2)

Abstract

Porcine circovirus 2 (PCV-2) is associated with a broad range of syndromes. In this study, 19 of 870 samples from pigs from different Brazilian states were found to be positive for PCV-2 by polymerase chain reaction (PCR). A fragment of 700 nt of the cap gene (ORF-2) from the 19 PCV-2-positive samples were sequenced using three pairs of primers (Fa/Ra, Fb/Rb and Fc/Rc). Maximum parsimony genealogy with a heuristic algorithm using the 19 field strain studied here, 21 sequences from GenBank and PCV-1 as an out-group showed the existence of two major clusters (A and B) and the Brazilian strains segregating in both of them. PCV-2 was found in pigs with various clinical signs. No association between clusters of PCV-2 and different states or clinical signs were observed, demonstrating that the exact role of PCV-2 in porcine circovirus diseases (PCVD) in Brazil still needs to be clarified. These results contribute to the molecular characterization of PCV-2, which serve as a basis for the epimiology of PCV-2 infection.

Genetic analysis of porcine circovirus type 2 (PCV2) strains isolated between 2001 and 2009: genotype PCV2b predominate in postweaning multisystemic wasting syndrome occurrences in eastern China

“…Porcine circovirus type 2 (PCV2) could be divided into two major genotypes based on sequencing analysis, but different nomenclature has been used, which are group 1 and 2, I and II, pattern 321 and 422, SG3 and SG1/SG2, A and B [8,[18][19][20]. Recently, Segale 0 s et al proposed that a standardized name for these genotypes, which were PCV 2a and 2b [11].…”

A proposal on porcine circovirus type 2 (PCV2) genotype definition and their relation with postweaning multisystemic wasting syndrome (PMWS) occurrence

“…Despite most sequencing studies did not find any relation between PCV2 sequences and the occurrence of the disease (Larochelle et al, 2002;Pogranichniy et al, 2002;Larochelle et al, 2003;de Boisseson et al, 2004;Grierson et al, 2004;Wen et al, 2005;Martins Gomes de Castro et al, 2007), some recent studies and field observations (Timmusk et al, 2005;Opriessnig et al, 2006;Cheung et al, 2007aCheung et al, , 2007bStevenson et al, 2007;Woodbine et al, 2007) have suggested the opposite. Moreover, epidemiological Danish and British studies strongly suggested that the spread of porcine circovirus diseases (PCVDs) is consistent with the introduction of a "new infectious agent" or a "new strain" of a known agent into a naïve population (Vigre et al, 2005;Woodbine et al, 2007).…”

PCV‐2 genotype definition and nomenclature

“…However, their nomenclature has become ‘research group-dependent’. Thus, genotypes ‘1’ and ‘2’ from Grau-Roma and others (2008) correspond, respectively, to groups ‘1’ and ‘2’ (Olvera and others 2007), ‘I’ and ‘II’ (De Boisséson and others 2004), ‘ sg3 ’ and ‘ g1/sg2 ’ (Timmusk and others 2008), ‘A’ and ‘B’ (Martins Gomes de Castro and others 2007), ‘b’ and ‘a’ (Gagnon and others 2007) and restriction fragment length polymorphism patterns ‘321’ and ‘422’ (Carman and others 2008). Therefore, in order to counteract the current scientific confusion on genotype names, the members of the eu consortium on porcine circovirus diseases (www.pcvd.org) propose a standardised nomenclature for pcv-2 genotypes.…”